Minimal adaptive notch filter for respiratory frequency tracking

摘要

A method based on the use of a minimal order adaptive notch filterable to monitor changes in the respiratory frequency is proposed. Thenotch frequency of the filter is updated via a recursive least squaredalgorithm. The respiratory frequency is tracked during spontaneous andcontrolled breathing in healthy young subjects. Results demonstratethat, even when paced, respiratory frequency is variable and itsvariability depends on the breathing rate